Revision Notes

Alkanes

The general formula for alkanes is as follows:

  • CnH2n+2   (where “n” is a constant)

The first ten members of the homologous series of the alkanes are:

  • CH4     (Methane)
  • C2H6     (Ethane)
  • C3H8     (Propane)
  • C4H10     (Butane)
  • C5H12     (Pentane)
  • C6H14     (Hexane)
  • C7H16     (Heptane)
  • C8H18     (Octane)
  • C9H20     (Nonane)
  • C10H22     (Decane)

Alkanes consist of strong covalent bonds therefore they are, on the whole, quite un-reactive. They do not react with acids, alkalis, and oxidising agents. Their most important reaction is that of combustion.

The main chemical reactions that alkanes undergo are:

  • Combustion
  • Substitution with halogens
  • Catalytic Cracking
Methane
Methane
Ethane
Ethane